Amion Acid - Radioactive Nitrogen

[Topmartinfan]

If I were to test a plant or animal for contamination of radioactive nitrogen(RN), would I test their levels of amino acid? I know amino acid contains nitrogen, and I am not sure if the levels of nitrogen would increase if they animal ate vegetation contanimated by the RN. I am so lost......... :hihi:

[bumab]

Levels of nitrogen would not increase. You could test their amino acids for radioactivity, which would tell you the plant took in radioactive N (some isotope, I don't recall which they usually use). Normal amino acids would not have a radioactive tracer, whereas contaminated a.a.'s would.

[Fishteacher73]

A lot of nitogen is not biologically available. It would depend on what form the radioactive N was in to be available for use biologically.

[UncleAl]

CRC Handbook:

 

Isotope Half-life

-------------------

N-12 11.00 msec

N-13 9.97 min

N-14 stable

N-15 stable

N-16 7.13 sec

N-17 4.17 sec

N-18 0.62 sec

N-19 0.3 sec

N-20 0.1 sec

 

Any "contamination" would have long since decayed away before you looked. You tag with N-15 and analyze with mass spectrometry. Look up the natural abundance of N-15 to quantify background contamination. Does biology fractionate isotopes?

[Fishteacher73]

For an organism to utilize N2, it must be biologically fixed. There are a number of bacteria that "fix" atmospheric N2 into biologically usable nitrogen in the form of (NH3). Dependng on what form the radioactive N is in, it may or may not be accessable for the plant to take in and utilize.

[Topmartinfan]

I am more confused now than I was before. haha I am taking a science class and there is a question that asks, "Remember the nuclear accident at Chernobyl in 1986? A scientist suspects that the food in a nearby ecosystem may have been contaminated with radioactive nitrogen over a period of months. Which substances in plants and animals could be examined for radioactivity to test his hypothesis?"

[C1ay]

I am more confused now than I was before. haha I am taking a science class and there is a question that asks, "Remember the nuclear accident at Chernobyl in 1986? A scientist suspects that the food in a nearby ecosystem may have been contaminated with radioactive nitrogen over a period of months. Which substances in plants and animals could be examined for radioactivity to test his hypothesis?"

You are the second student to ask the same question here. I wonder if you are both from the same school.

[Topmartinfan]

Thanks, Clay. I thought about amino acid as first, but I don't understand how the contamination gets there. Can we check for radioactive enzymes or what?? I just don't understand the process of how the AA become contaminated. Our body has some radioactive enzymes, right?? How would we tell the difference between the ones that are supposed to be there and the ones that are not?

[Fishteacher73]

you would have to have a comparison of a couple of "uncontaminated" samples and see what ratioo they occur naturally in the organism and compare that to your test sample.

[Topmartinfan]

you would have to have a comparison of a couple of "uncontaminated" samples and see what ratioo they occur naturally in the organism and compare that to your test sample.

 

So, I would test the amino acids for radioactive enzymes?

[C1ay]

So, I would test the amino acids for radioactive enzymes?

I think that would probably be the right place to start but I am not a biologist. Sorry I can't be of more help.

[Fishteacher73]

So, I would test the amino acids for radioactive enzymes?

 

Anything made from protiens would be possible. They would be easier to isolate as well as opposed to a specific enzyme (You would want to test the same substances to really produce a valid outcome). Plants are not really my bag, but any common protien would probably be good (Large sample size).

 

DNA would also be a viable option as well.

[Topmartinfan]

Anything made from protiens would be possible. They would be easier to isolate as well as opposed to a specific enzyme (You would want to test the same substances to really produce a valid outcome). Plants are not really my bag, but any common protien would probably be good (Large sample size).

 

DNA would also be a viable option as well.

 

First off, I really appreciate your help.

 

So, If I test the amino acid to see if it is radiated, I would then need to determine if the radioactivity is a 'normal radioactive enzyme' by comparing the samples to 'normal' aa from another animal/plant, which ever I am testing, right?

 

Does the radioactive nitrogen get into the aa from the water and or oxygen? Does the radiated oxygen or water molecules would bond to the aa molecule, right??

 

Sorry to be so ignorant, but I have to explain this using no less than 200 words. uuuggggg

[Fishteacher73]

So, If I test the amino acid to see if it is radiated, I would then need to determine if the radioactivity is a 'normal radioactive enzyme' by comparing the samples to 'normal' aa from another animal/plant, which ever I am testing, right?

 

Yes, because there is going to be a % of natuaural isotopes that occur. You would need to find a baseline for the "normal" concentrations.

 

 

 

Does the radioactive nitrogen get into the aa from the water and or oxygen? Does the radiated oxygen or water molecules would bond to the aa molecule, right??

 

I do not know for certain the method that it would enter the organism. If the N2 is atmospheric nitrogen that is radioactive it would enter I believe via water intake as nitrogen fixing bacteria converted it to NH3 in the root system. (Sorry for not being more precise, most plant dealings I have done are with aquatic plants and the mechanics are slightly different than those of terrestrial plants)

 

If the N is in some other form, ie integrated into some other molecule then introduced to the plant, it would really depend on the intial substance. Atmospheric N2 would also enter into the plant via the stomata durring respiration and could casue radioactive damage, but the N would not be incorporated into the plant, it would just pass in and out as it emmitted radiation.

 

Hopefully I have helped and not muddied the water worse..

[Topmartinfan]

Yes, because there is going to be a % of natuaural isotopes that occur. You would need to find a baseline for the "normal" concentrations.

 

 

 

 

 

I do not know for certain the method that it would enter the organism. If the N2 is atmospheric nitrogen that is radioactive it would enter I believe via water intake as nitrogen fixing bacteria converted it to NH3 in the root system. (Sorry for not being more precise, most plant dealings I have done are with aquatic plants and the mechanics are slightly different than those of terrestrial plants)

 

If the N is in some other form, ie integrated into some other molecule then introduced to the plant, it would really depend on the intial substance. Atmospheric N2 would also enter into the plant via the stomata durring respiration and could casue radioactive damage, but the N would not be incorporated into the plant, it would just pass in and out as it emmitted radiation.

 

Hopefully I have helped and not muddied the water worse..

 

You have done a wonderful job, and I really appreciate your help!!! I will explain proteins and amino acids and then go into how I think the plants and animals should be tested. Surely I can come up with 200 words. haha